Diabetes mellitus type 1 is a chronic disease in which the pancreas no longer produces enough insulin and the glucose in the blood cannot be absorbed into the cells of the body. The main symptom is hyperglycemia. After 10 to 15 years of disease long-term vascular complications including retinopathy, nephropathy, neuropathy, and macrovascular disease are seen. Among the most common long-term complications of diabetes, diabetic neuropathy (DN) is a significant source of morbidity and mortality. There is considerable uncertainty about the prevalence of DN due to a lack of large epidemiological studies and consensus on diagnostic criteria with data variation ranging from 5% to 100%. DN is thought to result from diabetic microvascular injury involving small blood vessels that supply nerves (vasa nervorum). It is a set of heterogeneous clinical syndromes that affect distinct regions of the nervous system, individually or combined. The investigators differentiate autonomic and peripheral neuropathy: Clinical presentation of autonomic neuropathy includes postural hypotension, vomiting, diarrhea, bladder paresis, impotence, sweating abnormalities, and gastric fullness. Peripheral neuropathy presents as altered pain sensations (dys-, para-, hypo- or hyperesthesia), burning, and either superficial or deep pain. The examination of choice for the diagnosis of peripheral neuropathy is to determine nerve conduction velocity.